Skip to main content

Tasimelteon (Oral)

Medically reviewed by Drugs.com. Last updated on Jan 2, 2022.

Commonly used brand name(s)

In the U.S.

  • Hetlioz
  • Hetlioz LQ

Available Dosage Forms:

  • Suspension
  • Capsule

Therapeutic Class: Central Nervous System Agent

Pharmacologic Class: Melatonin Receptor Agonist

Uses for tasimelteon

Tasimelteon is a melatonin receptor agonist used to treat non-24-hour sleep-wake disorder (Non-24) and night time sleep disturbances in patients with Smith-Magenis Syndrome (SMS).

Tasimelteon is available only with your doctor's prescription.

Before using tasimelteon

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For tasimelteon, the following should be considered:

Allergies

Tell your doctor if you have ever had any unusual or allergic reaction to tasimelteon or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Pediatric

Appropriate studies have not been performed on the relationship of age to the effects of tasimelteon capsules to treat Non-24 in children and night time sleep disturbances in children with SMS younger than 16 years of age. Safety and efficacy have not been established.

Appropriate studies have not been performed on the relationship of age to the effects of tasimelteon oral liquid to treat night time sleep disturbances in children with SMS younger than 3 years of age. Safety and efficacy have not been established.

Geriatric

Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of tasimelteon in the elderly. However, elderly patients may be more likely to have side effects after taking tasimelteon.

Breastfeeding

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Interactions with medicines

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking tasimelteon, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using tasimelteon with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.

  • Viloxazine

Using tasimelteon with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

  • Apalutamide
  • Capmatinib
  • Carbamazepine
  • Ciprofloxacin
  • Enoxacin
  • Enzalutamide
  • Fluvoxamine
  • Fosphenytoin
  • Givosiran
  • Lumacaftor
  • Mitotane
  • Pacritinib
  • Phenytoin
  • Rifampin
  • St John's Wort

Interactions with food/tobacco/alcohol

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other medical problems

The presence of other medical problems may affect the use of tasimelteon. Make sure you tell your doctor if you have any other medical problems, especially:

  • Liver disease, severe—Use is not recommended in patients with this condition.

Proper use of tasimelteon

Take tasimelteon exactly as directed by your doctor. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered.

Tasimelteon should come with a patient instructions leaflet. Read and follow these instructions carefully. Ask your doctor if you have any questions.

Use only the brand of tasimelteon that your doctor prescribed. Different brands may not work the same way.

Take tasimelteon without food, at the same time every night.

Swallow the capsule whole. Do not crush, break, or chew it.

To use the oral liquid:

  • Tasimelteon comes with an oral dosing syringe and a press-in bottle adapter.
  • Shake the bottle for at least 30 seconds before each use.
  • Press down on the child-resistant cap and twist the cap counterclockwise to open the bottle. Do not throw away the cap.
  • For first time use only: Remove the seal and insert press-in bottle adapter into the bottle. Press on the bottle adapter until it is even with the top of the bottle. Once in place, it should not be removed. Replace the child-resistant cap tightly by turning clockwise and shake well again for at least 30 seconds.
  • Push the plunger of the syringe completely down. Insert the syringe into the opening of the press-in bottle adapter as far as it will go.
  • Carefully turn the bottle upside down. Slowly pull back the plunger to withdraw the needed amount of medicine from the bottle. Line up the end of the plunger with the prescribed dose.
  • If you see air bubbles in the syringe, push in the plunger so that the liquid flows back into the bottle.
  • Leave the syringe in the bottle adapter and turn the bottle upright. Carefully remove the syringe from the bottle adapter. Replace with child-resistant cap.
  • Place the tip of the oral syringe in your child's mouth and toward the inside of their cheek. Slowly push the plunger all the way to give the entire dose and make sure your child has time to swallow the medicine.
  • Remove the plunger from the barrel of the oral syringe. Rinse the syringe barrel with water. When it is dry, put the plunger back. Do not wash the oral syringe in the dishwasher. Do not throw away the oral syringe.

Keep using tasimelteon for several weeks or months. It may take a while to work in some patients because of individual differences in circadian rhythms (body clock).

Dosing

The dose of tasimelteon will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of tasimelteon. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For oral dosage form (capsules):
    • For non-24-hour sleep-wake disorder:
      • Adults—20 milligrams (mg) once a day, taken 1 hour before bedtime.
      • Children—Use and dose must be determined by your doctor.
    • For nighttime sleep disturbances in SMS:
      • Adults and children 16 years of age and older—20 milligrams (mg) once a day, taken 1 hour before bedtime.
      • Children younger than 16 years of age—Use and dose must be determined by your doctor.
  • For oral dosage form (suspension):
    • For nighttime sleep disturbances in SMS:
      • Children 3 to 15 years of age—Dose is based on body weight and must be determined by your doctor.
        • Weighing more than 28 kilograms (kg)—20 milligrams (mg) once a day, taken 1 hour before bedtime.
        • Weighing 28 kg or less—0.7 milligram per kilogram (mg/kg) of body weight once a day, taken 1 hour before bedtime.
      • Children younger than 3 years of age—Use and dose must be determined by your doctor.

Missed dose

If you miss a dose of tasimelteon, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Ask your healthcare professional how you should dispose of any medicine you do not use.

Store the capsule in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Keep the oral liquid in the refrigerator. Do not freeze. The 48-mL bottle can be stored for 5 weeks and the 158-mL bottle can be stored for 8 weeks after first opening the bottle.

Precautions while using tasimelteon

It is very important that your doctor check your progress at regular visits. This will allow your doctor to see if the medicine is working properly and to decide if you should continue to take it.

Tasimelteon may cause some people to become drowsy, sleepy, or less alert than they are normally. It is best that some activities before bedtime should be limited after taking tasimelteon.

Since smoking may decrease the treatment effects of tasimelteon, it is best to avoid smoking while you are using it. If you have any questions about this, check with your doctor.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Tasimelteon side effects

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

More common

  • Bladder, lower back, or side pain
  • bloody or cloudy urine
  • difficult, burning, frequent, or painful urination

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

  • Body aches or pain
  • chills or fever
  • cough
  • ear congestion
  • headache
  • nightmares
  • runny or stuffy nose
  • sneezing

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.